They already have more J15 than Liaoning and Shandong can carry onboard. If that's what you meant by "reserve". And with J35 to be inducted in near future, there will be more naval fighter jets than the 3 aircraft carrier can carry.
Yes, they will keep some J15 (and J35 in future) on land base as "reserve", and they will used them as type conversion jets to train more pilots in PLA Navy Aviation University.
However, those old J11BH and J11BSH will not likely be returned to PLAN Aviation service in future, nor will they likely be kept as reserve for PLA Navy aviation, simply because of logistic reason.